1. Field of the Invention
This application relates to multi-vortical separator and more particularly to a separator in a pressure sealed enclosure that includes a plurality of regions containing fluid rotating in a vortical manner.
2. Description of the Prior Art
Cyclones and vortical separators for removing for removing particulate matter in a transport medium are known in the prior art. Cyclones rely on the principle of centrifugally removing particulate matter from a transport medium by rotating the medium in some confined enclosure. The particulate centrifugally removed from the transport medium falls to a collection bin while the cleansed air is guided by a conduit to the outlet of the cyclone. One class of device is described by Rastatter in U.S. Pat. No. 3,543,931. Operation of the described device relies on the use of a plurality of modules which are independently connected to a common header system. Each module, which includes a manifold system, is connected to a plurality of conical cyclones each of which is connected to the manifold system. Each module can be viewed as an independent cyclone containing fluid rotating in a vortical sense for separating material suspended in the fluid. Each cyclone unit is in fluid communication with the inlet to the cyclone, as well as with the outlet of the cyclone.
Multi-cyclones of this design have inherent problems. The multi-cyclones represent essentially a plurality of scaled down single cyclones of conventional design operating in fluid parallel communication. The Reynolds numbers of the rotating fluid within the cyclones are small and boundary layer growth along the inner walls of the cyclones become increasingly pronounced with diminishing vortex diameter. The boundary layer growth greatly impares the efficiency gains that theoretically can be achieved with a multi-cyclone device over a single cyclone. Below a certain vortex size, no improvements over a single cyclone can be attained. As a result, initial investment for multi-cyclones, as well as the cost for upkeep and repair, are substantially higher than for single cyclones.
Another such cyclone is described by Dygert in U.S. Pat. No. 2,941,621. Operation of the described cyclone (centrifugal separators) relies on the use of a rotating transport medium so as to centrifugally separate therefrom particulate matter suspended within the medium. The described device contains in one enclosure a plurality of tubular centrifugal separators for effecting the separation of the particulate from the transport medium. The inlet of each of the tubular separators is in fluid communication with the inlet to the multi-cyclone, and the outlet of each of the tubular separators is in fluid communication with the outlet of the multi-cyclone. Each of the tubular separators has a plurality of swirler vanes at the inlet to the separator for initiating vortical flow to the transport medium entering each tubular separator.
Devices of this design have inherent problems in that they are very sensitive to upstream disturbances and to the nature of the incoming flow. Additionally, the overall particulate separation efficiency usually suffers from losses due to the low quality and aerodynamic inefficiency of the swirler vanes. Dictated by cost efficiency considerations, the swirler vanes are usually in the form of arched flat plates rather than shaped foils. Thus in order to obtain sufficient and stable rotation of the inletted flow, eight or more vanes per cyclone chamber circumference must be provided. The cross-sectional area between vanes becomes relatively small and the device can suffer from clogging where materials that are prone to packing are to be separated from the transport medium.